scholarly journals Molecular determinants of the physicochemical properties of a critical prion protein region comprising residues 106–126

1999 ◽  
Vol 342 (1) ◽  
pp. 207-214 ◽  
Author(s):  
Mario SALMONA ◽  
Paolo MALESANI ◽  
Luca DE GIOIA ◽  
Stefano GORLA ◽  
Maurizio BRUSCHI ◽  
...  
Keyword(s):  
Prion Protein ◽  
Conformational Changes ◽  
Amyloid Fibrils ◽  
Physicochemical Characteristics ◽  
Cellular Prion Protein ◽  
Random Coil ◽  
Neuronal Cultures ◽  
Primary Neuronal Cultures ◽  
C Terminus ◽  
Molecular Determinants

Prion diseases are marked by the cerebral accumulation of conformationally modified forms of the cellular prion protein (PrPC), known as PrPres. The region comprising the residues 106-126 of human PrP seems to have a key role in this conformational conversion, because a synthetic peptide homologous with this sequence (PrP106-126) adopts different secondary structures in different environments. To investigate the molecular determinants of the physicochemical characteristics of PrP106-126, we synthesized a series of analogues including PrP106-126 HD, PrP106-126 A and PrP106-126 K, with L-His → D-His, His → Ala and His → Lys substitutions respectively at position 111, PrP106-126 NH2 with amidation of the C-terminus, PrP106-126 V with an Ala → Val substition at position 117, and PrP106-126 VNH2 with an Ala → Val substitution at position 117 and amidation of the C-terminus. The analysis of the secondary structure and aggregation properties of PrP106-126 and its analogues showed the following. (1) His111 is central to the conformational changes of PrP peptides. (2) Amidation of the C-terminal Gly126 yields a predominantly random coil structure, abolishes the molecular polymorphism and decreases the propensity of PrP106-126 to generate amyloid fibrils. (3) PrP106-126 V, carrying an Ala → Val substitution at position 117, does not demonstrate a fibrillogenic ability superior to that of PrP106-126. However, the presence of Val at position 117 increases the aggregation properties of the amidated peptide. (4) Amyloid fibrils are not required for neurotoxicity because the effects of PrP106-126 NH2 on primary neuronal cultures were similar to those of the wild-type sequence. Conversely, astroglial proliferation is related to the presence of amyloid fibrils, suggesting that astrogliosis in prion encephalopathies without amyloid deposits is a mediated effect rather than a direct effect of disease-specific PrP isoforms.

Prion Protein Aggregation Induced by Copper(II) and Heparan Sulfate. Pressure-dependent Switch of Reaction Pathways

2008 ◽  
Vol 63 (6) ◽  
pp. 747-755 ◽  
Author(s):  
Driss El Moustaine ◽  
Joan Torrent ◽  
Reinhard Lange
Keyword(s):  
Heparan Sulfate ◽  
Prion Protein ◽  
Conformational Changes ◽  
Atmospheric Pressure ◽  
Amyloid Fibrils ◽  
Copper Ions ◽  
Fibril Formation ◽  
Cellular Prion Protein ◽  
Reaction Pathways ◽  
Structural Alterations

Copper ions (Cu2+) and heparan sulfate (HS) are suspected to act as regulatory agents in the conversion of cellular prion protein (PrPC) to its infectious isoform. However, the mechanism of this reaction is still largely unknown. Our previous report suggested multidimensional pathways for structural alterations of PrP, which may be modulated by high pressure (HP). Here we use HP to investigate the effects of Cu2+ and HS binding on PrP conformational changes and assembly. In the presence of Cu2+, amyloid fibrils are formed only under HP. In contrast, in the presence of HS, fibrils are formed at atmospheric pressure, but not under HP. Both compounds appear to compete for the same binding site, since HS-supported fibril formation is quenched by Cu2+. Inversely, Cu2+- mediated fibril formation under HP is inhibited by HS.

scholarly journals The uptake of tau amyloid fibrils is facilitated by the cellular prion protein and hampers prion propagation in cultured cells

2020 ◽  
Vol 155 (5) ◽  
pp. 577-591 ◽  
Author(s):  
Elena De Cecco ◽  
Luigi Celauro ◽  
Silvia Vanni ◽  
Micaela Grandolfo ◽  
Edoardo Bistaffa ◽  
...  
Keyword(s):  
Prion Protein ◽  
Amyloid Fibrils ◽  
Cultured Cells ◽  
Cellular Prion Protein ◽  
Prion Propagation

scholarly journals Isolation of infectious, non-fibrillar and oligomeric prions from a genetic prion disease

Brain ◽  
2020 ◽  
Vol 143 (5) ◽  
pp. 1512-1524 ◽  
Author(s):  
Ilaria Vanni ◽  
Laura Pirisinu ◽  
Claudia Acevedo-Morantes ◽  
Razieh Kamali-Jamil ◽  
Vineet Rathod ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Amyloid Fibrils ◽  
Morphological Characteristics ◽  
Immunogold Labelling ◽  
Structural Features ◽  
Cellular Prion Protein ◽  
Proteinase K ◽  
Supernatant Fraction ◽  
C Terminus ◽  
Electron Microscopy Analysis

Abstract Prions are transmissible agents causing lethal neurodegenerative diseases that are composed of aggregates of misfolded cellular prion protein (PrPSc). Despite non-fibrillar oligomers having been proposed as the most infectious prion particles, prions purified from diseased brains usually consist of large and fibrillar PrPSc aggregates, whose protease-resistant core (PrPres) encompasses the whole C-terminus of PrP. In contrast, PrPSc from Gerstmann-Sträussler-Scheinker disease associated with alanine to valine substitution at position 117 (GSS-A117V) is characterized by a small protease-resistant core, which is devoid of the C-terminus. We thus aimed to investigate the role of this unusual PrPSc in terms of infectivity, strain characteristics, and structural features. We found, by titration in bank voles, that the infectivity of GSS-A117V is extremely high (109.3 ID50 U/g) and is resistant to treatment with proteinase K (109.0 ID50 U/g). We then purified the proteinase K-resistant GSS-A117V prions and determined the amount of infectivity and PrPres in the different fractions, alongside the morphological characteristics of purified PrPres aggregates by electron microscopy. Purified pellet fractions from GSS-A117V contained the expected N- and C-terminally cleaved 7 kDa PrPres, although the yield of PrPres was low. We found that this low yield depended on the low density/small size of GSS-A117V PrPres, as it was mainly retained in the last supernatant fraction. All fractions were highly infectious, thus confirming the infectious nature of the 7 kDa PrPres, with infectivity levels that directly correlated with the PrPres amount detected. Finally, electron microscopy analysis of these fractions showed no presence of amyloid fibrils, but only very small and indistinct, non-fibrillar PrPresparticles were detected and confirmed to contain PrP via immunogold labelling. Our study demonstrates that purified aggregates of 7 kDa PrPres, spanning residues ∼90–150, are highly infectious oligomers that encode the biochemical and biological strain features of the original sample. Overall, the autocatalytic behaviour of the prion oligomers reveals their role in the propagation of neurodegeneration in patients with Gerstmann-Sträussler-Scheinker disease and implies that the C-terminus of PrPSc is dispensable for infectivity and strain features for this prion strain, uncovering the central PrP domain as the minimal molecular component able to encode infectious prions. These findings are consistent with the hypothesis that non-fibrillar prion particles are highly efficient propagators of disease and provide new molecular and morphological constraints on the structure of infectious prions.

Neuronal fibrillogenesis: amyloid fibrils from primary neuronal cultures impair long-term memory in the crab Chasmagnathus

2003 ◽  
Vol 147 (1-2) ◽  
pp. 73-82 ◽  
Author(s):  
Arturo Romano ◽  
Annalucia Serafino ◽  
Ewa Krasnowska ◽  
Maria Teresa Ciotti ◽  
Pietro Calissano ◽  
...  
Keyword(s):  
Amyloid Fibrils ◽  
Long Term Memory ◽  
Neuronal Cultures ◽  
Primary Neuronal Cultures ◽  
Term Memory

scholarly journals Mapping the Prion Protein Using Recombinant Antibodies

1998 ◽  
Vol 72 (11) ◽  
pp. 9413-9418 ◽  
Author(s):  
R. Anthony Williamson ◽  
David Peretz ◽  
Clemencia Pinilla ◽  
Hadyn Ball ◽  
Raiza B. Bastidas ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Cell Surface ◽  
Prion Protein ◽  
Disease Process ◽  
Cellular Prion Protein ◽  
Epitope Region ◽  
Molecular Events ◽  
C Terminus ◽  
Phage Display Libraries ◽  
Recombinant Molecule

ABSTRACT The fundamental event in prion disease is thought to be the posttranslational conversion of the cellular prion protein (PrPC) into a pathogenic isoform (PrPSc). The occurrence of PrPC on the cell surface and PrPSc in amyloid plaques in situ or in aggregates following purification complicates the study of the molecular events that underlie the disease process. Monoclonal antibodies are highly sensitive probes of protein conformation which can be used under these conditions. Here, we report the rescue of a diverse panel of 19 PrP-specific recombinant monoclonal antibodies from phage display libraries prepared from PrP deficient (Prnp0/0) mice immunized with infectious prions either in the form of rods or PrP 27-30 dispersed into liposomes. The antibodies recognize a number of distinct linear and discontinuous epitopes that are presented to a varying degree on different PrP preparations. The epitope reactivity of the recombinant PrP(90-231) molecule was almost indistinguishable from that of PrPC on the cell surface, validating the importance of detailed structural studies on the recombinant molecule. Only one epitope region at the C terminus of PrP was well presented on both PrPC and PrPSc, while epitopes associated with most of the antibodies in the panel were present on PrPCbut absent from PrPSc.

scholarly journals The structural transformation comparison of the human Prion protein mutants V176G, E196A, and I215V by using molecular dynamics simulation

2021 ◽  
Author(s):  
Ashraf Fadhil Jomah ◽  
Sepideh Parvizpour ◽  
Jafar Razmara ◽  
Mohd Shahir Shamsir
Keyword(s):  
Prion Protein ◽  
Aqueous Media ◽  
Point Mutations ◽  
Cellular Prion Protein ◽  
Dynamics Simulation ◽  
Globular Domain ◽  
Salt Bridges ◽  
Wild Type ◽  
Structural Determinants ◽  
C Terminus

Abstract The point mutations in the gene coding of prion protein (PrP) originate human familial prion protein (HuPrP) diseases. Such diseases are caused by several amino acid mutations of HuPrP including V176G, I215V, and E196A located at the second, third native helix and in their loop, respectively. Determining the transition from cellular prion protein (PrPc) to pathogenic conformer (PrPSc) in the globular domain of HuPrP that results in pathogenic mutations is the key issue. The effects of mutation on monomeric PrP are detected in the absence of an unstructured N-terminal domain only. A MD simulation for each of these wild type mutants is performed to examine their structure in the aqueous media. The structural determinants are discerned to be different for wild-type HuPrP (125–228) variants compare to that of HuPrP mutations. These three mutations exhibiting diverse effects on the dynamical properties of PrP are attributed to the variations in the secondary structure, solvent accessible surface areas (SASAs), and salt bridges in the globular domain of HuPrP. High fluctuations that are evidenced around residues of the C-terminus of the helix 1 for V176G cause Gerstmann-Straussler-Scheinker (GSS) syndrome. Conversely, the occurrence of fluctuations around residues of helix 2, helix 3, and the loss of salt bridges in these regions for E196A and I215V mutants is responsible for Creutzfeldt-Jakob disease. Furthermore, small changes in the overall SASAs mutations strongly influence the intermolecular interactions during the aggregation process. The comparative results in this study demonstrate that the three mutants undergo different pathogenic transformations.

scholarly journals The uptake of tau amyloid fibrils is facilitated by the cellular prion protein and hampers prion propagation in cultured cells

2020 ◽  
Author(s):  
Elena De Cecco ◽  
Luigi Celauro ◽  
Silvia Vanni ◽  
Micaela Grandolfo ◽  
Adriano Aguzzi ◽  
...  
Keyword(s):  
Prion Protein ◽  
Amyloid Fibrils ◽  
Cultured Cells ◽  
Neuroblastoma Cells ◽  
Cellular Prion Protein ◽  
Brain Diseases ◽  
Gene Encoding ◽  
Prion Propagation ◽  
Prion Conversion ◽  
Tau Fibrils

AbstractTauopathies are prevalent, invariably fatal brain diseases for which no cure is available. Tauopathies progressively affect the brain through cell-to-cell transfer of tau protein amyloids, yet the spreading mechanisms are unknown. Here we show that the cellular prion protein (PrPC) facilitates the uptake of tau aggregates by cultured cells, possibly by acting as an endocytic receptor. In mouse neuroblastoma cells, we found that tau amyloids bind to PrPC; internalization of tau fibrils was reduced in isogenic cells devoid of the gene encoding PrPC. Antibodies against N-proximal epitopes of PrPC impaired the binding of tau amyloids and decreased their uptake. Surprisingly, exposure of chronically prion-infected cells to tau amyloids reduced the accumulation of aggregated prion protein; this effect lasted for more than 72 hours after amyloid removal. These results point to bidirectional interactions between the two proteins: whilst PrPC mediates the entrance of tau fibrils in cells, PrPSc buildup is greatly reduced in their presence, possibly because of an impairment in the prion conversion process.

scholarly journals Aβ oligomers induce sex-selective differences in mGluR5 pharmacology and pathophysiological signaling in Alzheimer mice

2019 ◽  
Author(s):  
Khaled S. Abd-Elrahman ◽  
Awatif Albaker ◽  
Jessica M. de Souza ◽  
Fabiola M. Ribeiro ◽  
Michael G. Schlossmacher ◽  
...  
Keyword(s):  
Metabotropic Glutamate Receptor ◽  
Cellular Prion Protein ◽  
Neuronal Cultures ◽  
Primary Neuronal Cultures ◽  
Aβ Oligomers ◽  
Metabotropic Glutamate ◽  
High Affinity ◽  
Mouse Cortex ◽  
Aβ Oligomer

ABSTRACTSex is a key modifier of the prevalence and progression of Alzheimer’s disease (AD). β- Amyloid (Aβ) deposition is a pathological hallmark of AD and aberrant activation of metabotropic glutamate receptor 5 (mGluR5) by Aβ has been linked to AD progression. We find that mGluR5 exhibits distinct sex-dependent pharmacological profiles. Specifically, endogenous mGluR5 from male mouse cortex and hippocampus binds with high-affinity to Aβ oligomers whereas, female mGluR5 exhibits no affinity to Aβ oligomers. The binding affinity of mGluR5 to Aβ oligomer is dependent on its interaction with cellular prion protein (PrPC) as mGluR5 co-immunoprecipitates with PrPC from male, but not female, mouse brain. Aβ oligomers also bind with high-affinity to human mGluR5 in male, but not female, cortex. The mGluR5/Aβ oligomer/PrPC ternary complex is essential to elicit mGluR5-dependent pathological signaling and as a consequence mGluR5-regulated GSK3β/ZBTB16 autophagic signaling is dysregulated in male, but not female, primary neuronal cultures. These sex-specific differences in mGluR5 signaling translate into in vivo differences in mGluR5-dependent pathological signaling between male and female AD mice. We show that the chronic inhibition of mGluR5 using a mGluR5-selective negative allosteric modulator reactivates GSK3β/ZBTB16-regulated autophagy, mitigates Aβ pathology and reverses cognitive decline in male, but not female, APPswe/PS1ΔE9 mice. Thus, it is evident that, unlike male brain, mGluR5 does not contribute to Aβ pathology in female AD mice. This study highlights the complexity of mGluR5 pharmacology and Aβ oligomer-activated pathological signaling and emphasizes the need for clinical trials redesign and analysis of sex-tailored treatment for AD.

Aβ oligomers induce pathophysiological mGluR5 signaling in Alzheimer’s disease model mice in a sex-selective manner

2020 ◽  
Vol 13 (662) ◽  
pp. eabd2494
Author(s):  
Khaled S. Abd-Elrahman ◽  
Awatif Albaker ◽  
Jessica M. de Souza ◽  
Fabiola M. Ribeiro ◽  
Michael G. Schlossmacher ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Male Mouse ◽  
Disease Model ◽  
Cellular Prion Protein ◽  
Neuronal Cultures ◽  
Primary Neuronal Cultures ◽  
Aβ Oligomers ◽  
High Affinity ◽  
Amyloid Aβ

The prevalence, presentation, and progression of Alzheimer’s disease (AD) differ between men and women, although β-amyloid (Aβ) deposition is a pathological hallmark of AD in both sexes. Aβ-induced activation of the neuronal glutamate receptor mGluR5 is linked to AD progression. However, we found that mGluR5 exhibits distinct sex-dependent profiles. Specifically, mGluR5 isolated from male mouse cortical and hippocampal tissues bound with high affinity to Aβ oligomers, whereas mGluR5 from female mice exhibited no such affinity. This sex-selective Aβ-mGluR5 interaction did not appear to depend on estrogen, but rather Aβ interaction with cellular prion protein (PrPC), which was detected only in male mouse brain homogenates. The ternary complex between mGluR5, Aβ oligomers, and PrPC was essential to elicit mGluR5-dependent pathological suppression of autophagy in primary neuronal cultures. Pharmacological inhibition of mGluR5 reactivated autophagy, mitigated Aβ pathology, and reversed cognitive decline in male APPswe/PS1ΔE9 mice, but not in their female counterparts. Aβ oligomers also bound with high affinity to human mGluR5 isolated from postmortem donor male cortical brain tissue, but not that from female samples, suggesting that this mechanism may be relevant to patients. Our findings indicate that mGluR5 does not contribute to Aβ pathology in females, highlighting the complexity of mGluR5 pharmacology and Aβ signaling that supports the need for sex-specific stratification in clinical trials assessing AD therapeutics.

scholarly journals Interaction between Shadoo and PrP Affects the PrP-Folding Pathway

2015 ◽  
Vol 89 (12) ◽  
pp. 6287-6293 ◽  
Author(s):  
Danica Ciric ◽  
Charles-Adrien Richard ◽  
Mohammed Moudjou ◽  
Jérôme Chapuis ◽  
Pierre Sibille ◽  
...  
Keyword(s):  
Prion Protein ◽  
Conformational Changes ◽  
Conversion Rate ◽  
Biochemical Characterization ◽  
Direct Interaction ◽  
Cellular Prion Protein ◽  
Dominant Negative ◽  
Folding Pathway ◽  
Replication Process ◽  
Binding Behavior

ABSTRACTPrion diseases are characterized by conformational changes of a cellular prion protein (PrPC) into a β-sheet-enriched and aggregated conformer (PrPSc). Shadoo (Sho), a member of the prion protein family, is expressed in the central nervous system (CNS) and is highly conserved among vertebrates. On the basis of histoanatomical colocalization and sequence similarities, it is suspected that Sho and PrP may be functionally related. The downregulation of Sho expression during prion pathology and the direct interaction between Sho and PrP, as revealed by two-hybrid analysis, suggest a relationship between Sho and prion replication. Using biochemical and biophysical approaches, we demonstrate that Sho forms a 1:1 complex with full-length PrP with a dissociation constant in the micromolar range, and this interaction consequently modifies the PrP-folding pathway. Using a truncated PrP that mimics the C-terminal C1 fragment, an allosteric binding behavior with a Hill number of 4 was observed, suggesting that at least a tetramerization state occurs. A cell-based prion titration assay performed with different concentrations of Sho revealed an increase in the PrPScconversion rate in the presence of Sho. Collectively, our observations suggest that Sho can affect the prion replication process by (i) acting as a holdase and (ii) interfering with the dominant-negative inhibitor effect of the C1 fragment.IMPORTANCESince the inception of the prion theory, the search for a cofactor involved in the conversion process has been an active field of research. Although the PrP interactome presents a broad landscape, candidates corresponding to specific criteria for cofactors are currently missing. Here, we describe for the first time that Sho can affect PrP structural dynamics and therefore increase the prion conversion rate. A biochemical characterization of Sho-PrP indicates that Sho acts as an ATP-independent holdase.

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